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he stole from peering into the future):
the “Burman Bullfrog Battery” — the
greatest known power source for
small portable devices — and building
a Robot Mother, the core of the story.
He could never go back to any
place in the future that he had already
visited, but on one trip to the future,
he came upon some very interesting
drawings of something that piqued his
interest, so he spent days carefully
copying all the details.
He spent a long time building this
‘something’ that he had no clue as to
what it was.
When the refrigerator-sized was
completed, he sat and watched it.
Suddenly, a tiny trapdoor opened and
a mechanical ‘mouse’ darted out and
out of his house.
As time passed and there were
more of these ‘mice’ leaving the
Robot Mother and returning with
watches and similar things stolen from
people or jewelry stores, people
discovered that you would be slashed
by a razor on some of the mice if you
tried to catch one.
Neighborhood cats met
their maker and Burman
quickly realized that he had
created a nightmare.
You should look this
story up as it is very inspiring
and a bit of a horror story,
but emphasizes people’s lack
of knowledge about technical
things — especially robots.
Robots Require a Lot
I usually place the need for better
robot power sources and
breakthrough battery technology at
the top of the list of critical needs for
So many people simply don’t
know just how much power is
required to operate large-sized mobile
robots — especially bipedal walking
The kids that participate in the
FIRST Robotics Competition certainly
soon realize just how much power is
required for a 120 pound robot. Our
local Anacortes, WA Cyborg Ferrets
FIRST Team 3238 had the rollout of
their entrant the other night to a large
crowd, as seen in Figure 9.
Besides the large mobility motors
for the wheels, other power-hungry
motors are required for lifting and
Having just moved here, I jumped
in late as a mentor to help where I
could in the mechanical and electrical
aspects. I would encourage any of you
readers to do the same with your own
local school’s FIRST robotics groups. It
is most satisfying.
Large mobile robots in years’ past
used heavy lead-acid batteries that
were also fairly dangerous when
tipped over. New sealed lead-acid
batteries soon became the norm in
the late ‘70s and ‘80s, and are still
used today for many robot designs.
When portable hand power tools
became popular in the ‘70s, nickel-cadmium batteries were the primary
choice, and soon became popular for
small to mid-sized robots as they had
a slightly better power density (W/kG)
Available in single AA sizes
(though C and D were also available)
and battery packs of ‘sub Cs,’ they
were the norm for years, despite their
tendency to develop a ‘memory
effect’ when improperly discharged or
charged too early. At 1.2 volts per cell,
that didn’t match regular AA cells; it
took five NiCad cells to equal four
Nickel metal hydride batteries
were next in the progression of
battery technology that also had 1.2
volts per cell, but up to five times the
power density by weight compared to
the NiCad (nickel-cadmium) and lead-acid cells. These batteries are still the
preferred cells for home robot vacuum
Figure 9. Anacortes, WA FIRST Team 3238 FRC robot.
Figure 10. Tesla Model S battery pack requires over 7,000 individual cells.